Electronic industry is flourishing and various kinds of electronic product are quite popular. The narrowing-down in size and the lightening on weights is the most important for the manufacture of portable electronic product. For the convenience in portation, batteries have become a usual electricity storage component. Thus, power can be supplied for electronic product anywhere.
Most of the current portable electronic devices adapt reusable lithium-ion battery which has large battery capacity and large energy density. A semi-finished battery of a lithium-ion battery has a plurality of anode electrodes, a plurality of cathode electrodes and insulation films which are in a pile. Electrolyte is finally filled into the semi-finished battery to complete the lithium-ion battery. In such a structure, the distance between the anode and the cathode of the semi-finished battery matters a lot. By the current practice, the anode and the cathode of hoe semi-finished battery are separated by said insulation film; namely, the insulation film made said distance between the anode and the cathode. However, in the corresponding process, said distance may be shrunk due to the cut burrs, unexpected particles or unevenly material thickness, inducing the unwanted short circuit between the anode and the cathode.
Though an insulation test is usually performed during the process, the main test item by now is hi-pot test and tends to cause misjudgement of device under test (DUT) due to long energy transition time and considerable capacitor deviation (about ±20%). Besides, there's only a little difference between the scales of the steady state and the non-stead state of the semi-finished battery cell, thus an accurate determination may not be achieved.